FAS and cancer: To date, studies showed that the Fas‐670A/G, Fas‐1377G/A, and FasL‐844T/C polymorphisms might be associated with increased risk of certain cancers, including breast cancer 18, 19, 20, 21, gastric cancer 22, 23, cervical cancer 24, 25, lung cancer 26, 27, etc. Several studies have reported the potential association between Fas/ FasL polymorphisms and risk of esophageal cancer 28, 29.